GB2334179A

GB2334179A - Local Call Routing in a Mobile communications System

Info

Publication number: GB2334179A
Application number: GB9802366A
Authority: GB
Inventors: Kevan Hobbis; Robert Ivor Davies
Original assignee: Motorola Ltd
Current assignee: Motorola Solutions UK Ltd
Priority date: 1998-02-04
Filing date: 1998-02-04
Publication date: 1999-08-11
Also published as: GB9802366D0

Abstract

For local communication, such as in building calls serviced by pico cells, a common base station controller (14) manages the calls avoiding reference to the mobile services switching centre (16) and thereby avoiding service charges. The base station controller (14) controls switching through the local PBX (12).

Description

METHOD AND SYSTEM FOR ROUTING IN A COMMUNICATION SYSTEM Field ofthe Invention The present invention relates to a local management system for a cellular communication system.

Badqwonnsl of the Invention Development is currently being made on sub-cells of cellular systems, for example on pico-cells which can be provided within a particular building.

These sub-cells can provide improved call quality and increased system capacity.

Summary of the Invention The present invention seeks to provide a local routing path for a subcellular communication architecture, in particular for a pico-cell.

According to an aspect of the present invention, there is provided a method of controlling communication between stations in local or adjacent sub cells of a cellular communications system, including the steps of determining whether a station being called is located within the same or an adjacent sub-cell as the calling station, which same or adjacent sub cell is controlled by a common base station controller, and routing the call through the common base station controller without reference to a mobile services switching controller.

Local routing which avoids the mobile services switching controller can avoid network charges, thereby enabling the establishment of free local calls. This can be particularly useful for a large organisation operated within a building.

Preferably, the base station controller controls switching of the calls through a local private branch exchange (PBX).

Advantageously, the sub cells are pico cells, each pico cell being serviced by a pico base station controller.

According to another aspect of the present invention, there is provided a system for controlling communication between stations in local or adjacent sub cells of a cellular communications system, including a common base station controller coupled to control calls in a single sub cell or in adjacent sub cells and operable to determine whether a station being called is located within the same or an adjacent sub-cell as the calling station, and to route the call through the common base station controller without reference to a mobile services switching controller.

Brief Description of the Drawing An embodiment of the present invention is described below, by way of example only, with reference to the accompanying drawing, in which the sole figure is a schematic view of an embodiment of architecture for a picocell of a cellular communications system.

Detailed Description of a Prerred Embodiment The preferred embodiment provides local routing of signals, for example for a pico-cell to be located in a building. Referring to the figure, the example shown is a local cellular communications site for a large corporate organisation which has a number of pico-base stations PicoBTS1-PicoBTSn. The pico-base stations may, for example be provided on each floor of the building 10 and are each connected to a single PBX system 12.

The pico-base stations PicoBTS1-PicoBTSn are coupled to a common base station controller (BSC) 14, of substantially conventional form, which is responsible for communicating with the mobile services switching centre (MSC) 16, in known manner.

Conventionally, any calls to or from a mobile station (not shown) are routed through the base station controller 14 to the mobile services switching centre 16.

However, in the preferred embodiment, calls for which both the sending and the receiving stations are within the same building are routed locally by the base station controller 14 in conjunction with the local private branch exchange (PBX), without transfer to the mobile services switching centre 16. Likewise a call between a mobile station and a fixed station connected to the PBX can be routed locally without transfer to the mobile services centre or the public fixed line telephone system.

This can enable calls routed locally to be free of network charges normally applied on usage of the mobile services switching centre and can provide for improved call quality.

Various call examples are given below. In these examples, the base station controller 14 is assumed to be located remote from the in building pico-cell.

Fixed Station to Mobile Station Calls Local routing of such calls can be achieved by the base station controller 14 monitoring the EuroISDN signalling from the PBX to the mobile services switching centre 16 and monitoring for common circuit numbers. Further reference can be found in prior British patent application 9616794.5 ny Motorola Ltd.

This example provides for local routing also for calls which originate from the PBX through pico-base station PicoBTS1 and which terminates at a mobile in the pico-cell serviced by, for example, PicoBTS2. In order to achieve this, the base station controller 14 is coupled to the PBX and operable to instruct the PBX to route a call to a different pico-base station, thereby enabling local routing within the site. The base station controller 14 uses an appropriate signalling path to instruct the PBX to set up a call to a different pico-base station PicoBTS1-PicoBTSn for the PBX to instruct the base station controller 14 to route the call locally rather than through the MSC 16.

In order to implement this example, the base station controller 14 is designed to support full signalling protocol between the PBX and the MSC 16. When a PBX call is set up, that is to or from a PBX, the base station controller 14 intervenes and terminates the call, making an onward call to the actual destination. This allows the call re routing for fixed station to mobile station calls to be achieved transparently with respect to the MSC 16.

Mobile Station to Mobile Station Calls Local routing of mobile to mobile calls can also be achieved by the base station controller 14 monitoring the EuroISDN signalling from the PBX to the mobile services switching centre 16 and by monitoring for common circuit numbers as for fixed station to mobile station calls.

As in the case of fixed station to mobile station calls, the base station controller 14 is designed to set up a connection through the PBX from one pico-base station to another. The base station controller 14 performs the switching of calls to this local path, thereby establishing local routing and avoiding communication through the MSC 16.

The structure of the base station controller 14 and software required will be readily apparent to the skilled person having regard to the teachings herein.

Claims

CLAIMS 1. A method of controlling communication between stations in local or adjacent sub cells of a cellular communications system, including the steps of determining whether a station being called is located within a same or an adjacent sub-cell as a calling station, which same or adjacent sub cell is controlled by a common base station controller, and routing a call through a common base station controller without reference to a mobile services switching centre.
2. A method according to claim 1, wherein the common base station controller controls switching of the call through a local private branch exchange (PBX).
3. A method according to claim 1 or 2, wherein the sub cells are pico cells, each pico cell being serviced by a pico base station controller.
4. A method according to any preceding claim, wherein routing of calls through the common base station controller is carried out for calls within a building.
5. A system for controlling communication between stations in local or adjacent sub cells of a cellular communications system, including a common base station controller coupled to control calls in a single sub cell or in adjacent sub cells and operable to determine whether a station being called is located within a same or an adjacent sub-cell as a calling station, and to route a call through a common base station controller without reference to a mobile services switching centre.
6. A system according to claim 5, wherein the common base station controller is coupled to a local private branch exchange (PBX) and is operable to control switching of the call through the local private branch exchange.
7. A method according to claim 5 or 6, wherein the sub cells are pico cells, each pico cell being serviced by a pico base station controller coupled to the common base station controller.
8. A method of controlling communication between stations in local or adjacent sub cells of a cellular communications system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.
9. A system for controlling communication between stations in local or adjacent sub cells of a cellular communications system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.